With civilian radio production suspended for the duration in 1942, many radio dealers were in search of additional lines of business to fill the gap. The September 1942 issue of Radio Retailing offered a number of suggestions involving applications of photocells. Above, with the possibility of wartime blackouts, a business owner would need a way to shut off his electric sign quickly in case the order was given. One way to do it automatically would be to wire the sign to a photocell pointed at the closest streetlight. When the town shut off the streetlights, his sign would immediately go dark.

Various industrial applications were suggested, as well as, of course, use of electric eyes in security systems. Shown at right was a design used the by Cleveland Plain Dealer, to measure the pitching speeds of various pitchers. A trailer was equipped with the system shown here, and the player was to pitch into an opening in the back of the trailer. The ball would pass through two beams of light, and from the difference in time, the speed would be measured.

Of course, today, the aspiring major league pitcher can get the same thing surprisingly inexpensively. The device shown here uses radar to measure the ball’s speed and does not require an entire trailer to move around.

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